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Parasitism
A symbiotic relationship that benefits one organism and harms another is called parasitism. A parasite is an organism that gets its nutrition from the tissues of another organism without killing it. The organism on which the parasite lives is called the host. Although parasites usually do not kill their hosts, they often weaken them. Parasitism can be a limiting factor. In a parasitic relationship, one organism (the parasite) lives in or on another organism (the host), which is usually harmed by the parasite. Almost all organisms have some parasites, but the parasites usually do not cause death because death of the host would result in death of the parasites. However, if a host has too many parasites, the host might die. Thus, the limitation is the number of parasites that the host is carrying.
There are two kinds of parasites. Those that live outside or on the body of the host is called ectoparasites or external parasites.
Examples of this kind of parasites are: a. Mosquito b. Lice c. Flea d. Ticks e. Leech The parasites that live inside the body of the host are called endoparasites or internal parasites. Some examples of this kind of parasites are: a. Ascaris or roundworm b. Hookworm c. Tapeworm d. Fluke e. Trichine spirale |
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If we love our children, we must love the earth with tender care and pass it on, diverse and beautiful, so that on a warm spring day 10000 years hence they can feel peace in a sea of grass, can watch a bee visit a flower, can hear a sandpiper call in the sky, and can find joy in being alive. ~Hugh H. Iltis |
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